Lead The Way
by Omoni
Summary: Some plot-what-plot lewff involving a dumb human cult movie, a collar, and Alphys and Undyne. Yes, this means smut. What did you expect? And no, I have no idea. I just wrote it for fun - and to see if I could. I don't expect anyone to read this, either o o.


One night, Alphys surprised Undyne, whom in turn surprised her. They had both been signaling to each other for most of the night the desire for sex, and Alphys had a specific reason why, one she'd managed to keep a secret from Undyne for an entire week. It was a Friday night - also part of her plan. as she knew, if she were successful, they'd both need a day to recover - when she finally brought it up.

She'd been bored one day during a lunch break when an absurd idea came over her, one she remembered bringing up with Undyne only once, after a lot of blushing and fogged glasses, only to be laughed off. They'd gone to see a ridiculous human cult movie with Mettaton, Papyrus, and sans (Mettaton's idea, Papyrus's future nightmare fuel, and sans's boredom cure - so he'd hoped) and had sat snickering through all of it while Mettaton fumed, Papyrus covered his eyes, and sans surfed UnderNet, bored.

However, one thing alone Alphys actually found intriguing, and when they were alone, she'd asked Undyne, blushing, "Some of it... the non-stupid stuff... was kinda... i-interesting, huh?"

Undyne blushed in return, blinking. "Uh," she muttered, scratching at her cheek "Like what?"

"Er," Alphys looked down, her glasses fogging up. "The-the... the..." She gestured around her neck, before adding, "Nevermind!"

Undyne, however, was scarlet, staring at her wife with a new eye. "Me, too!" she admitted. Alphys looked up at her in shock, then they both laughed to tears. Nothing came of it then, but Alphys never forgot.

So that bored lunch hour she surfed the selections, found one she knew would fit both of them (in case she was wrong. [She was.]), and ordered it without a second thought. She kept it barely a secret for the entire week, and now, finally, she could share it.

"So, uhm..." Alphys shifted a little, bright red, as Undyne was reaching back to unhook her bra. "Mm?" Undyne murmured against her shoulder, and Alphys shivered, unable to help it. "I-I have a surprise for... for us... for tonight... uh." She shut up when Undyne leaned back to face her, having successfully unhooked aforementioned bra and was now interested in this surprise.

"Oh? What kind?" Undyne was grinning. Any time Alphys had a surprise to show her in bed, it was usually a kind of outfit that always got Undyne hot and bothered, and she delighted in removing those outfits very, very slowly.

Alphys bit her lip, looked away, and smiled shyly. "Er... just... close your eyes!" Undyne did, and Alphys both shrugged off her bra and reached to her nightstand and grabbing a small, shiny clothed bag. She held it in both hands, shaking from both anticipation and nervousness. "Here," she said, holding it out to Undyne, who opened her eye and took it, bemused.

"I, uh, figured you'd want me to wear it..." Alphys was saying, as Undyne slowly opened the bag and looked inside, her blood igniting the moment her brain processed what it was. "B-because you're so s-strong and..."

Undyne already had pulled it out and was buckling it around her own neck, her face pink and her smile huge. It fit perfectly; a collar made of imitation leather, dark green, with a generous clasp dangling from the front big enough for a lead or a finger or two to grab onto. The moment it was secured in place, Undyne shut her eyes, threaded a finger through the clasp, and actually shuddered, sighing deeply.

"Okay..." Alphys said weakly, her own body feeling hot, now. "Not what I was expecting at all." She was not unable to look away, the look of pleasure on Undyne's face not one she'd ever seen before - but suddenly realised she liked it very much.

"I think I really like this," Undyne breathed out, sitting up and kneeling in front of Alphys. "I didn't know you knew, Alphy. _I_ didn't even know until I saw that stupid movie!"

"I... same here," Alphys agreed. "But I thought... you'd want t-to be... you'd want me to wear it..." She pointed to her own neck, and Undyne blinked in surprised. "B-because you're a-already so in c-control..."

"No way!" Undyne grinned. "Alphy, I want to be _yours._ I want to follow you. Most of all... most of all..." She looked away, her smile crooked. "I want to _please you."_ She looked back and licked her lips, and Alphys swallowed, hard. "So, Alphy," Undyne said, her eye dark, now, "Tell me what you want me to do."

Those words had quite an effect on Alphys, who had never before known this side to herself until she heard her wife utter that one, simple sentence. She'd always thought of herself as the weak one, the perfect bottom and never one to take control very often. Therefore, when suddenly - and literally - faced with Undyne demanding her to order her around sexually... it definitely effected her quite deeply.

"Don't get a nosebleed," Undyne grinned, and Alphys blushed, actually worried that that would happen.

Undyne laughed and leaned on her, looking up at her with a sparkling eye, and Alphys sighed. "You know I wouldn't be able to help it if I had!"

"I do, Mistress," Undyne replied with a grin.

Alphys's eyes flared, her whole body flashing hot again at that. She had had no idea she had this side to herself, but apparently either Undyne did, or was just incredibly lucky at guessing (it was the former). "D-did you just...?"

"Yes, Mistress," Undyne grinned up at her, Sliding her arms around Alphys's waist. Alphys stared at her, barely able to think, now.

Well, maybe not completely. "S-so, what I-I want, you'll... you'll d-do?"

Undyne nodded. "Yes, Mistress. Well, I'll tell you if I don't want to," she admitted, and Alphys nodded in agreement, glad for that. "But I don't think that'll be an issue..." She leaned close and whispered, "Right, Mistress?"

Alphys stared at her, then reached forward and pulled her close, one hand going to Undyne's cheek, the other hooking a claw around the clasp of the collar and pulling her closer, kissing her deeply. Undyne's eye closed, her arms tightening around Alphys's waist, a small sound coming from her throat when she was pulled close.

Against her lips, Alphys said, her voice sharp, "Get naked." Undyne pulled away slowly, nodding and sitting up to push down her shorts and underwear together, her eye still on Alphys with every move.

"Okay," Alphys said in that same tone. "Now, me." Undyne came back and reached down, undoing the button and zipper of Alphys's jeans and pulling them down, Alphys balancing to make it easier, her hands caressing Alphys's legs and thighs as she slid them down. Once the jeans were tossed aside, she did the same with Alphys's underwear, leaning down and tailing her lips down her legs this time. Alphys lay back, unable to keep her balance at this, overwhelmed, and Undyne smiled at her.

Then, Undyne pulled away and sat down on her knees again, her eye shining. "Now what, Mistress?" she asked, slightly breathless.

Alphys sat up and kissed her, throwing her arms around Undyne's neck and pulling her down onto the bed with her. "Kiss me," Alphys ordered, her voice getting stronger, "all the way down." She was amazed by her own boldness, but oddly she found it was very arousing, especially when Undyne grinned and licked her lips again.

"You've got it, Mistress," she purred, leaning down to lick slowly from Alphys's lips to to her neck, biting lightly, and Alphys shut her eyes, reaching out and grabbing onto Undyne's shoulders. She kept her hold until Undyne dipped down to her chest, and her hands grabbed onto the bed instead, as now Undyne licked slowly along first one, then the other, nipple of each breast. Her attention was slow and careful, and Alphys squirmed a bit, unable to help it.

Undyne trailed her tongue slowly along Alphys's ribcage, then belly, then lower, until finally she was nestled between Alphys's legs, looking up at her with a grin and a red face, Alphys looked down, and Undyne said, "Now what, Mistress?"

Alphys stared at her, and she could see the glow of teasing deep in her eye; she knew what was 'now what', but fully intended to play it for what it was worth. "Undyne...!" Alphys said, unable to keep the slight whine from her voice. "Please, please, _please_ keep going!"

In reply, Undyne lay down on her front, propped herself up on her elbows, and leaned down, kissing along the inside of one of Alphys's thighs slowly. Alphys sighed, relaxing and closing her eyes, only to shift when Undyne's tongue finally licked along her centre, lingering ever-so-slighting over her clit before diving between to lick directly to her core. Alphys breathed out a small moan in reply.

Undyne loved to go down on Alphys. There was something almost intoxicating about the way she tasted and the way she reacted when tasted that drove Undyne crazy at times. Alphys reached down and sought one of her hands, which she offered, and Alphys held it tight, her other hand, Undyne saw, at her chest and over one of her own breasts. That also had a profound effect on Undyne, as seeing her wife so aroused that she got lost in it was one of her biggest turn-ons. With another purr, she closed her eyes and licked deeper, flicking the tip of her tongue occasionally over Alphys's clit - which in turn had Alphys's claws digging into Undyne's hand, deeper with each lick.

"Undyne," Alphys whispered, her eyes still closed. "Use your fingers... too..."

Undyne opened her eye, looked up at her, and saw that she was staring back, her eyes glazed over and face red. Undyne nodded, bringing her free hand down to slowly stroke already wet and hot flesh, before pushing two deep, her tongue now focussing on her clit. Alphys shut her eyes again tight, heat and pleasure lancing through her each time Undyne's fingers pushed deep.

Undyne loved watching her, her own breaths quick and her heart quicker. Alphys rarely lost control, so when she did, it was quite wonderful to see. When Undyne crooked her fingers up slightly and rubbed gently within Alphys, her wife cried out, a sound Undyne adored, so much that she could feel her arousal grow. Closing her eye again, she focussed on those sounds, pulling her other hand away in order to grab hold of Alphys's hip to keep her as in place as possible.

Alphys was squirming now, one hand over her mouth and trying to muffle already loud sounds, her other hand digging into the bed beneath her. Undyne wanted her to lose that last bit of control, to hear her voice unmuffled, so she increased the speed of her fingers and flicked her tongue over her clit even closer.

Alphys was gasping now, barely able to see, let alone breathe. She was so close, everything Undyne doing so incredible and in just the right ways... When Undyne's fingers suddenly pressed down deep inside her, Alphys lost it, and she groaned out Undyne's name desperately, both hands clutching at the mattress, arching her back, and throwing her head back as she came - and came hard. It was incredible, how amazing this climax felt, and Undyne worked to making it feel as best as she could.

"Breathe, please, Mistress," Undyne said sharply, jerking her head up in sudden alarm, and Alphys did, gasping for air. It was so easy to forget to breathe when one felt like a wispy cloud of pleasure about to float away...

Undyne slowly pulled her fingers free, licking them off with a small sigh, closing her eye in pleasure. Alphys lay there, her hands loosely holding the blanket beneath her, her eyes shut and her breath raspy. Undyne crawled slowly up the length of her side, then curled up against Alphys and whispered, "Was that nice, Mistress Alphy?"

 _"Oh,"_ Alphys burst out, "A-am- _amazing!"_ But then she surprised Undyne - no small feat, that - by opening her eyes and staring at her. _"We're not done,"_ she suddenly said, her voice stronger. Undyne blinked, actually bemused by this, but Alphys sat up and reached for her, hooking her by the collar again and pulling her into a deep, blood-igniting kiss. Undyne whimpered against Alphys's lips, still rather turned on by her own actions as well as he wife's, and Alphys responded by licking her lips apart and kissing her harder. Quite suddenly Undyne found herself pinned down, and Alphys pressed closer, so close she could fee her heart racing against her own.

Alphys reached down and slipped her hand between Undyne's legs, fingers reaching up and deep, and Undyne shifted against her touch, her eye closing. She reached up and wrapped her arms around Alphys, who in turn kissed her closer, and again Undyne whimpered.

"Alphy," she whispered against Alphys's lips, and in reply, Alphys pressed down and pulled her hand away to shift herself between her legs. She reached up and pulled Undyne's arms away from around her, holding her by the wrists and pinning them above her head. Undyne's eye closed and she sighed deeply, then shifted when Alphys's knee went between her legs. Undyne hooked her legs around Alphys's leg and murmured desperately. _"Please,_ Mistress," she begged brokenly, and Alphys nodded, leaning down and licking Undyne's neck slowly.

Alphys pushed close, and Undyne shifted against her, matching her move for move, Alphys starting slow, wanting it to last. Undyne, however, felt already half-crazy with need, and instead pushed up against her with a moan, trying to urge Alphys to move faster. Alphys could never resist Undyne when she was like this, so she obliged. This time, Undyne was the one crying out, her hands clenched as Alphys kept them pinned above her head. They kissed again, and Undyne arched up, the sound of Alphys's name strangled as she broke from the kiss to say it. Alphys knew what that meant and held her down as she came, her eye shut tight and her teeth bared, her breath catching just a bit.

Alphys let go of one of Undyne's wrists to stroke the hair away from her face slowly, as Undyne went limp beneath her, her own body following suit. With a shudder, Alphys relaxed, resting her head on Undyne's shoulder, her hold on Undyne's other wrist going slack. She closed her eyes, slipping her hand down from Undyne's hair to her neck, tracing the collar slowly before hooking her claw through it again.

Undyne swallowed hard hard, whispering, "No more yet, please, Mistress..."

Alphys smiled. "I agree," she admitted, keeping her eyes shut. "Undyne, that was... that was..."

"Hot?" Undyne offered with a grin.

"Yes. And incredible. We've never had sex like that before."

"Your fault," Undyne said tiredly. "You bought the thing."

"Yes, but you wearing it..." Alphys snuggled closer. "I wasn't expecting that."

"Your reactions..." Undyne replied. "I knew you had it in you."

"I didn't," Alphys admitted, blinking at the memory of her bossing Undyne around - Undyne, of all people, and in this context, too. "But you're right. Something about you... about your wanting me... I-I liked it."

Undyne opened her eye and gazed up at her. "I loved it."

"So I guess that movie wasn't complete garbage," Alphys concluded.

"No, it was, but it had at least one good idea." Undyne paused. "Don't tell Mettaton. We'd never live it down."

Alphys laughed. It was true, after all.

 **The End**


End file.
